1. Field of the Invention
The present invention relates to a projection display apparatus applied to a liquid crystal projector or the like.
2. Description of the Related Art
A projection display apparatus (for example, a liquid crystal projector) is being spread, which displays a picture by spatially modulating incident light on a spatial light modulation device in accordance with an electric signal applied to the spatial light modulation device, outputting the modulated light, and collecting and projecting the outgoing light. Such a projection display apparatus has generally a lamp as a light source, a condenser, and an illumination optical system for condensing light generated from the lamp and the condenser and making the condensed light enter the spatial light modulation device. Light from the spatial light modulation device is projected by a projection lens onto a screen or the like.
Among such projection display apparatuses, in an apparatus for combining three primary color light of red light (R), green light (G), and blue light (B) (so-called 3-modulation-panel projection display apparatus), variations may occur in the precision and the like of fixation of an optical system. In this case, there is an issue such that out-of-color-registration occurs due to misregistration between primary color lights in a display image projected on a screen. To reduce out-of-color-registration caused by optical-mechanism factors, a projection display apparatus having a registration adjusting function of electrically correcting out-of-color-registration has been proposed (for example, Japanese Unexamined Patent Application Publication No. H08-201937).